Institut Sophia Agrobiotech

UMR INRA - Univ. Nice Sophia Antipolis - Cnrs

http://www.paca.inra.fr/institut-sophia-agrobiotech_eng/

Plant-Oomycete Interactions

The team is currently studying mechanisms underlying interactions between plants and microbes in order to contribute to alternative pest control strategies. Our research programs, mainly conducted on plante-oomycete* interactions, aim at identifying molecular processes that orchestrate, on the pathogen side, the onset and the development of infection and the associated evolutive processes. We also aim at deciphering plant responses, leading to the success (sensitivity) or the failure (resistance) of the infection. We combine plant pathology, cell biology, evolutionary and functional genomics, biochemistry and molecular biology.

Current priorities

Which genes are involved in the definition and evolution of Phytophthora host specificity ?

Which plant functions favor pathogen penetration and the success of infection ?

Can we define the relationships of plant pathogen oomyetes with their biotic environment?

How can we stimulate plant defenses in order to improve resistance ?

Biological models studied

Oomycetes :

Phytophthora spp. pathogenic to solanaceous hosts

Phytophthora parasitica, hemibiotrophic root pathogen

Hyaloperonospora arabidopsidis, biotrophic leaf pathogen

Plants :

Model plant : Arabidopsis thaliana

Plants of economical interest: Solanaceae family (tomato, pepper…)

Scientific expertise

The originality of the group relies in developing research efforts on both partners under conditions of susceptibility as well as of resistance. In addition, our respective know-how and the structure of our team favour the contribution of our different studies to the definition of a collective, multifaceted project that is conducted at different levels:

- structure and function of oomycete pathogenicity effectors

- comparative geomics and transcriptomics on complete genomes

- adaptive repsonses of pathogen populations to the selection pressure of crops in the field

Application

Our research aims at proposing novel targets for the control of plant pathogenic oomycetes. These targets might be used for the development of efficient oomycides, and for the creation of new resistance ressources in plants.

See also

*Oomycetes are eukaryotic microorganisms that include devastative plant pathogens, and then constitute a major threat to agriculture and environment worldwide. Pathogenic species from the genera Phytophthora and Pythium, as well as some obligate pathogens (Bremia, Plasmopara…) generally cause major damages on virtually all dicot plants, and may also attack cereals and subsistence crops. The importance of oomycete diseases during the XIXth century (potato blight leading to the Irish famine, vine mildew, citrus gummosis…) throughout the world is at the origin of Phytopathology as a genuine scientifical disipline, and substantially shaped the bases of modern crop protection, through the development of chemical control and breeding for resistance.

Despite similar physiological and ecological traits shared with fungi, oomycetes display phylogenetic affinities with diatoms and brown algae among Chromalveolates, that include dinoflagellates and several animal pathogens (Plasmodium,Toxoplasma, Theileria...). As a consequence of this taxonomical position, most traditional fungicide molecules are generally poorly efficient, because they have been developed against true pathogenic fungi. In addition, adaptive potential of oomycetes in response to their environment leads to a rapid breakdown of varietal resistances. So, the development of integrated management strategies that would be more efficient and environmentally friendly implies a better knowledge on the mechanisms that govern oomycete physiology and pathogenicity.